Atmósfera <h3>Focus and Scope</h3> <p dir="ltr">Atmosfera is an international, peer-reviewed journal published quarterly since 1988, devoted to original research in the atmospheric sciences and climate change, and interactions with the hydrosphere, cryosphere, biosphere and human systems. </p> <p>It is published by the Universidad Nacional Autónoma de México, through the Instituto de Ciencias de la Atmósfera y Cambio Climático.</p> <p>All papers published are Open Access for readers and there are no publication fees for authors. The journal is indexed in Scopus, SCimago, Science Citation Index, LatinIndex, SciELO, among other databases. It has continuously increased its visibility and impact, with an annual Impact Factor of 1.106 (2020) and a 3-year average of 1.466, as determined by the Journal Citation Report (Clarivate/ Web of Science).</p> <!-- WIDGET SCImago - Open Access --> <p><a title="SCImago Journal &amp; Country Rank" href=";tip=sid&amp;exact=no"><img src="" alt="SCImago Journal &amp; Country Rank" border="0" /></a> <img style="float: right; width: 256px; height: 93px;" src="" alt="Atmósfera - CCA UNAM" /></p> <!-- WIDGET SCImago - Open Access --> en-US <p>Once an article is accepted for publication, the author(s) agree that, from that date on, the owner of the copyright of their work(s) is Atmósfera.</p><p>Reproduction of the published articles (or sections thereof) for non-commercial purposes is permitted, as long as the source is provided and acknowledged.</p><p>Authors are free to upload their published manuscripts at any non-commercial open access repository.</p> (Graciela B. Raga) (Irene Romero Nájera) Fri, 01 Apr 2022 00:00:00 -0600 OJS 60 Changes to tropical eastern North Pacific intraseasonal variability under global warming, implications for tropical cyclogenesis <p class="p1">Changes to the tropical eastern North Pacific Intraseasonal Oscillation (ISO) at the end of the 21st century and implications for tropical cyclone (TC) genesis are examined in the Shared Socioeconomic Pathways (SSP585) scenario of the Coupled Model Intercomparison Project phase 6 (CMIP6) data set. Multimodel mean composite low-level wind and precipitation anomalies associated with the leading intraseasonal mode indicate that precipitation amplitude increases while wind amplitude weakens under global warming, consistent with previous studies for the Indo-Pacific warm pool. The eastern North Pacific intraseasonal precipitation/wind pattern also tends to shift southwestward in a warmer climate, associated with weaker positive precipitation anomalies near the coast of Mexico and Central America during the enhanced convection/westerly wind phase. Implications for the modulation of TC genesis by the leading intraseasonal mode are then explored using an empirical genesis potential index (GPI). In the historical simulation, GPI shows positive anomalies in the eastern North Pacific in the convectively enhanced phase of the ISO. The ISO’s modulation of GPI weakens near the coast of Mexico and Central America with warming, associated with a southward shift of GPI anomalies. Further examination of the contribution from individual environmental variables that enter the GPI shows that relative humidity and vorticity changes during ISO events weaken positive GPI anomalies near the Mexican coast with warming and make genesis more favorable to the southwest. The impact of vertical shear anomaly changes is also to favor genesis away from the coast. These results suggest a weaker modulation of TCs near the Mexican Coast by the ISO in a warmer climate.</p> Hien X. Bui, Eric D. Maloney Copyright (c) 2021 Atmósfera Fri, 01 Apr 2022 00:00:00 -0600 Stratospheric temperature features over Saudi Arabia and their relationship to Atlantic SSTs and surface temperatures in winter <p class="p1">Stratospheric temperature is an important climatic factor regionally and globally. This paper investigates temperature trends in the lower stratosphere at 50 hPa (T50), the mid-stratosphere at 30 hPa (T30), and the upper stratosphere at 10 hPa (T10), as well as their impacts on Atlantic Ocean sea surface temperature (SST) and Saudi Arabian surface air temperature (SAT) during the entire winter seasons of 1979-2019. The results show significant cooling for the T50 linear trend, progressive cooling for the T30 linear trend, and cooling for the T10 linear trend during the study period over Saudi Arabia. The results also indicate a significant nonlinear cooling trend for stratospheric temperature at T50 and T30, while a weak cooling at T10 is observed. Abrupt climatic changes towards warmth exist at all three levels of stratospheric temperature, which occur in 1992 for T50 and T30 and in 1983 for T10. These abrupt climate changes may be related to volcanic eruptions. Our results also indicate that a strong negative relationship exists between T50 and the SST of the tropical South Atlantic (TSA) and the Atlantic Multi-Decadal Oscillation (AMO), while T30 indicates a statistically negative relationship with the AMO. The lead-lag cross-correlation suggests that the SST of the Atlantic Ocean (tropical North Atlantic [TNA], TSA, and AMO) are linked to stratospheric temperatures at three lead winters. As a result of the teleconnection between SAT and stratospheric temperature over Saudi Arabia, the coupling of these two features occurs in winter, especially in the lower to mid-stratosphere layers.</p> H. M. Hasanean, Abdulhaleem H. Labban Copyright (c) 2021 Atmósfera Fri, 01 Apr 2022 00:00:00 -0600 Evaluation of the WRF-ARW model during an extreme rainfall event: Subtropical storm Guará <p class="p1">This study simulates an unusual extreme rainfall event that occurred in Salvador city, Bahia, Brazil, on December 9, 2017, which was named subtropical storm Guará and had precipitation of approximately 24 mm within less than 1 h. Numerical simulations were conducted using the Weather Research and Forecasting (WRF) model over three domains with horizontal resolutions of 9, 3, and 1 km. Different combinations of seven microphysics, three cumulus, and three planetary boundary layer schemes were evaluated based on their ability to simulate the hourly precipitation during this rainfall event. Statistical indices (MB = –0.69; RMSE = 4.11; MAGE = 1.74; r = 0.55; IOA = 0.66; FAC2 = 0.58) and time series plots showed that the most suitable configurations for this weather event were the Mellor-Yamada-Janjić, Grell-Freitas, and Lin formulations for the planetary boundary layer, cumulus, and microphysics schemes, respectively. The results were compared with the data measured at meteorological stations located in Salvador city. The WRF model simulated well the arrival and occurrence of this extreme weather event in a tropical and coastal region, considering that the region already has intense convective characteristics and is constantly influenced by sea breezes, which could interfere in the model results and compromise the performance of the simulations.</p> Yasmin Kaore Lago Kitagawa, Erick Giovani Sperandio Nascimento, Noéle Bissoli Perini Souza, Pedro Junior Zucatelli, Prashant Kumar, Taciana Toledo de Almeida Albuquerque, Marcelo Romero de Moraes, Davidson Martins Moreira Copyright (c) 2021 Atmósfera Fri, 01 Apr 2022 00:00:00 -0600 Friction velocity estimation using a 2D sonic anemometer in coastal zones <p class="p1">Friction velocity (<em>u</em><sub>*</sub>) is an important velocity scale used in the study of engineering and geophysical flows. The widespread use of 2D sonic anemometers in modern meteorological stations makes the estimation of <em>u</em><sub>*</sub> from just the horizontal components of the velocity a very attractive possibility. The presence of different wind regimes (such as sea breezes in or near coastal zones) causes the turbulent parameters to be dependent on the wind direction. Additionally, <em>u</em><sub>*</sub> depends on atmospheric stability, whch makes the estimation of <em>u</em><sub>*</sub> from 2D measurements very difficult. A simple expression is proposed, and then tested with data from six independent experiments located in coastal zones. The results show that it is possible to estimate friction velocity from 2D measurements using the turbulence intensity as a proxy for <em>u</em><sub>*</sub>, reducing substantially the sensitivity to the wind direction or atmospheric stability, with small root mean squared errors (0.06 &lt; RMSE &lt; 0.097) and high correlation coefficients (0.77 &lt; r<sup>2 </sup>&lt; 0.95).</p> Bernardo Figueroa-Espinoza, Zulia Sánchez-Mejía, Jorge Maximiliano Uuh-Sonda, Paulo Salles, Luis Méndez-Barroso, Hugo Alberto Gutiérrez-Jurado Copyright (c) 2021 Atmósfera Fri, 01 Apr 2022 00:00:00 -0600 Application of a ground-based microwave radiometer in aviation weather forecasting in Indian Air Force <p class="p1">Time and intensity-specific very short-term forecasting or nowcasting is the biggest challenge faced by an aviation meteorologist. Ground-based microwave radiometer (MWR) has been used for nowcasting convective activity and it was established that there is a good comparison between thermodynamic parameters derived from MWR and GPS radiosonde observations, indicating that MWR observations can be used to develop techniques for nowcasting severe convective activity. In this study, efforts have been made to bring out the efficacy of MWR in nowcasting thunderstorms and fog. Firstly, the observations of MWR located at Palam, New Delhi, India have been compared with the nearest radiosonde data to ascertain the variation in respective profiles. Large differences were found in relative humidity (RH), whereas temperatures from MWR were found to be close to radiosonde observed temperature up to 3.5 km. Subsequently, the scatter plots and correlation coefficients of thermodynamic indices/parameters indicated that most of the parameters are either not correlated or have moderate correlation only for 12:00 UTC profiles. The superepoch technique of lagged composite for various thermodynamic indices/parameters to obtain a combined picture of all the thunderstorm and dense fog cases on the time series could not determine any pattern to predict thunderstorm and dense fog with lead time of 2-4 hours. MWR profile for a case of occurrence of thunderstorm was analyzed. No significant variation was observed in most of the indices (as calculated from MWR observed parameters) prior to the occurrence of thunderstorm. RH at freezing level and between 950 and 700 hPa levels were the only parameters, which increased four hours prior to the occurrence.</p> Savitesh Mishra, Shreya Pandit, Ashish Mittal, Velampudi Sudarshan Srinivas Copyright (c) 2021 Atmósfera Fri, 01 Apr 2022 00:00:00 -0600 Spatial and temporal changes of land uses and its relationship with surface temperature in western Iran <p class="p1">A split-window algorithm has been used in the Ilam dam watershed to determine the relationship between land surface temperature (LST) and types of land use. Landsat satellite images of the TM sensor for 1990, 1995, 2000, 2005 and 2010 and Landsat 8 (OLI Sensor) for 2015 and 2018 are used. After geometric and radiometric corrections of satellite images, land use maps are extracted by using the fuzzy ARTMAP method. An accuracy assessment showed that the highest value of the kappa coefficient was 94% with a total accuracy of 0.95 for 2015, and the lowest kappa coefficient value was 87% with a total accuracy of 0.9 for 1990. The high values of these coefficients indicate the acceptable accuracy of using Landsat’s remote sensing data for land use detection. The most important land use change is related to dense forest and sparse forest land uses, with decreases of 20.07 and 17.04%, respectively. The minimum LST measures in 1990, 2010, and 2018 in dense forest are 21.27, 30.55 and 33.82 ºC, respectively. The maximum LSTs for the sparse forest land use in 1990 and 2010 are 52.48 and 56.09, and 56.10 ºC for the dense forest land use in 2018. As a result, the average LST in agricultural lands was lower than in sparse forest and rangeland;, which is mainly due to the high moisture content and the greater evapotranspiration rate. Land use/land cover variations from 1990 to 2018 show that all land uses have experienced an increase in LST.</p> Noredin Rostami, Hassan Fathizad Copyright (c) 2021 Atmósfera Fri, 01 Apr 2022 00:00:00 -0600 Assessment of bioclimatic sensitive spatial planning in a Turkish city, Eskisehir <p class="p1">The city of Eskişehir is located in the Central Anatolia Region of Turkey, where harsh continental climatic characteristics are prevalent (i.e., cold winters and hot summers). In recent years, quality and quantity of studies on bioclimatic comfort have increased both all over the world and in Turkey. Outdoor bioclimatic comfort conditions are counted amongst the indicators of human quality of life in urban environments, together with other physical, social and economic features such as air quality, GDP, and possibilities of social activities. The calculated values representing bioclimatic comfort conditions have been used instead of individual mean values of some climatic elements, in order to provide an insight of the liveability of a city. The aim of the present research study is to determine: (1) hourly bioclimatic comfort conditions in the Eskişehir city center during sultry summer days, considering bioclimatic comfort values calculated according to 12-year data from urban, sub-urban and rural areas using the physiological equivalent temperature (PET) index and RayMan software for the calculation of solar radiation fluxes on individuals in the hottest five months of the year; (2) the spatial distribution of these comfort values in decades (10-day intervals) using Geographic Information Systems and raster maps, taking into consideration elevation and land use; and (3) which urban design and planning principles could be adopted to deal with adverse thermal comfort conditions triggered by the urban heat island (UHI) effect. The results of the study indicate that the poorest comfort conditions are provided in urban areas, while rural areas are more advantageous in terms of comfort conditions. New bioclimatic-sensitive urban design principles are taken into consideration to create more comfortable areas from the bioclimatic perspective (i.e., windier and less humid sites open to the prevalent wind direction and out of heat stress).</p> Süleyman Toy, Savaş Çağlak, Aslıhan Esringü Copyright (c) 2021 Atmósfera Fri, 01 Apr 2022 00:00:00 -0600 Regional extreme rainfall estimation in the Middle Black Sea Region, Turkey <p class="p1">The occurrence probabilities of heavy rainfall that cause flood events have an essential role in designing water-related structures and water resource management. In many cases, data for analysis are either not available or are insufficient for reliable design of water-related structures. Regional frequency analysis is usually preferred to provide design information in sites with especially inadequate data available. Our study applied L-moment procedures to annual maximum rainfall series from 70 gauging stations in the Middle Black Sea Region (MBSR) of Turkey to estimate regional rainfall quantiles. The first attempt for regionalization aimed to evaluate the entire area as an homogeneous region. The sub-regions were initially defined with the ward’s clustering algorithm due to the presence of discordant sites under a presumption of a single homogeneous region. In compliance with the results of the discordancy and heterogeneity measures, the most promising classification was achieved with six clusters (sub-regions) that satisfied the homogeneity condition as “acceptably homogeneous”. It was decided that the GEV and GLO distributions in five sub-regions, the GNO distribution in four sub-regions, and the PE3 distribution in three sub-regions, were acceptable as regional frequency distributions. In comparison, GPA was not a candidate distribution in any of the six sub-regions.</p> Kadri Yürekli, Melih Enginsu, Muberra Erdogan Copyright (c) 2021 Atmósfera Fri, 01 Apr 2022 00:00:00 -0600 Economic disparities in pollution-related mortality in three municipalities of the Metropolitan Area of the Valley of Mexico <p class="p1">This study explored the nature of health risks in the population of three municipalities within the Metropolitan Area of the Valley of Mexico (MAVM) by means of an empirical analysis of health effects associated with air pollution and temperature variation. Based on the environmental justice theory, we asked whether, in unequal socioeconomic municipalities of the MAVM, the association between PM<sub>10 </sub>concentrations and mortality depends on socioeconomic disparities. We differ from previous studies that have established a relationship between PM<sub>10 </sub>and mortality based on a state-space model instead of the Poisson regression model. The state-space model allows estimating the size of the unobserved at-risk population, its hazard rate, the life expectancy of individuals in that population, and the effect of changes in environmental conditions on that life expectancy. Our results show a lower hazard rate in a wealthy municipality, as compared to a higher hazard rate in a poor one. The lower hazard rate of the wealthy municipality extends life expectancy and enhances the likelihood of inhabitants staying long-lasting within the population at risk, thus increasing the size of that population, as compared to the population at risk in the poor municipality, whose members show a lower life expectancy. Thus, the smaller the at-risk population, the sicker its average member and the smaller the impact on long-term mortality. Our study examines how regional health disparities could provide information for public health policy initiatives which might improve living conditions among different communities.</p> Alejandro Islas-Camargo, Alok K. Bohara, J. Mario Herrera Ramos Copyright (c) 2021 Atmósfera Fri, 01 Apr 2022 00:00:00 -0600 Characterization of particulate matter in the iron ore mining region of Itabira, Minas Gerais, Brazil <p class="p1">Itabira has in its territory the largest complex of opencast mining in the world, located close to residential areas of the city. The air quality monitoring network installed in the city is the main source of particulate matter (PM) emission data. However, these air quality stations only cover the areas near the mines and do not measure fine particulate matter (PM<sub>2.5</sub>). Thus, a first field campaign was carried out to characterize PM in the city and to compare high volume data from air quality stations with the dichotomous air sampler data. Results of trajectories’ cluster analysis showed a long-range transport of aerosols during the sampling days from northeast (84% of the trajectories), east-southeast (12%), and south-southwest (3%) directions. Regarding the meteorological conditions during the sampling days, negative correlations were seen between coarse particulate matter (PM<sub>10</sub>) from mostly air quality stations and all meteorological parameters (but temperature). Results of the X-ray fluorescence and principal component analyses showed that the main trace elements in the coarse (PM<sub>2.5-10</sub>) and fine modes (PM<sub>2.5</sub>) are iron and sulfur, associated with emissions from mining activities, air mass transport from regional iron and steelmaking industry activities, vehicle emissions, local and regional biomass burning, and natural biogenic emissions. This work is the first assessment of source apportionment done in the city. Comparisons with other studies, for some large metropolitan areas, showed that Itabira has comparable contributions of sulfur, iron and elements such as copper, selenium, chromium, nickel, vanadium and lead.</p> Ana Carolina Vasques Freitas, Rose-Marie Belardi, Henrique de Melo Jorge Barbosa Copyright (c) 2021 Atmósfera Fri, 01 Apr 2022 00:00:00 -0600